1. Field of the Invention
The present invention relates to the control and measurement of flowrates for fluids, and in particular, to an assembly for controlling and measuring or sensing the flowrate of fluids.
2. Description of the Prior Art
A rotameter is a well-known device that measures the flowrate of fluid in a closed tube. It belongs to a class of meters called variable area meters, which measure flowrate by allowing the cross-sectional area of the fluid traveling through, to vary, causing a measurable effect. Unfortunately, rotameters cannot be used to measure flowrate at high pressures because they are typically made out of glass.
There are also other techniques and devices to measure flowrates, for example, turbine meters and venturi tubes (delta P). However, these devices do not accurately measure flowrates at the low end (e.g., turn-down ratios below 20-to-1) of the flow.
Thus, there remains a need to provide a device for accurately measuring fluid flowrates, even at high pressures.